Wet-pipe sprinkler system, method of supplying water and dealing with water leak in the sprinkler system

ABSTRACT

A wet-pipe sprinkler system, method of supplying water to the system, and method of dealing with a leakage of the system are provided, wherein the wet-pipe sprinkler system includes a sprinkler head; a plurality of interconnected pipes for supplying water to the sprinkler head; at least one water supply connected to one end of the pipes; an electric main valve for controlling inflow of water to the pipes; an electric drain valve to drain water from the pipes; a first electrical control circuit in a central control studio which outputs a drain valve opening signal to the electric drain valve and a main valve closing signal to the electric main valve when a leakage is detected, thereby blocking the water from entering the pipes and draining the water from the pipes. Accordingly, a leak may be dealt with promptly, thereby minimizing damage caused by the leakage.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a sprinkler system. Moreparticularly, the present invention relates to a wet-pipe sprinklersystem, a method of supplying water and dealing with water leak in thesprinkler system.

[0003] 2. Description of the Related Art

[0004] A sprinkler system is an automatic fire-fighting system installedin the ceiling of a building or a structure. The system includes asprinkler head that operates according to ambient thermal conditions, aseries of interconnected pipes through which water is supplied to thesprinkler head, and at least one water supply. In general, there are twotypes of sprinkler systems: a wet-pipe sprinkler system and a dry-pipesprinkler system. In a wet-pipe sprinkler system, a sprinkler head isfilled with water. In a dry-pipe sprinkler system, the pipes are filledwith air. The present invention relates to a wet-pipe sprinkler system.

[0005] A wet-pipe sprinkler system typically includes a main pipethrough which water is supplied to a sprinkler head from a water supplyand an auxiliary pipe on which the sprinkler head is installed. A mainvalve, which controls the overall inflow of the water from the watersupply to the sprinkler system, is installed in the main pipe. Thesprinkler head includes a heat fusible cap that tightly shuts an orificeduring normal situations (i.e., no fire present), but automaticallybreaks to pieces and detaches from the sprinkler head during a fire. Inthe wet-pipe sprinkler system, both the auxiliary pipe and the main pipeare filled with water under a predetermined pressure, e.g., at apressure of 6 kgf/cm². Therefore, in order to extinguish a fire, watercan be rapidly discharged from the orifice when the heat fusible capcomes off the sprinkler head and the sprinkler head operates.

[0006] However, there are some problems associated with a conventionalwet-pipe sprinkler system. First, a conventional wet-pipe sprinklersystem is vulnerable to a physical phenomenon referred to as “waterhammering” during the filling of a pipe with water. Water hammering isdue to a rapid change in pressure of the water contained in a pipecaused by a sudden change in kinetic energy. The rapid change inpressure directly affects a pipe, thus generating a vibration andimpulse noise therein. In a worst-case scenario, flooding of neighboringareas is caused by damage to a pipe. Therefore, it is important toprevent water hammering from occurring during the filling of a pipe withwater. Water hammering frequently occurs when the main valve is openedto fill a pipe with water because the pressurized water from the watersupply suddenly enters the pipe. For this reason, in the past, thesprinkler system was filled with water only by a water-filling pipeconnected to the main pipe with the main valve closed, and the mainvalve was opened after the filling. In the above method, a pipe having asmaller diameter than the main pipe is used as a water-filling pipe sothat water does not flow into the pipe too rapidly, thereby preventingwater hammering. However, since the opening and shutting of the mainvalve is manipulated by a person, e.g., a system manager, waterhammering may occur in a case where the main valve is mistakenly openedby the system manager before the sprinkler system is completely filled.

[0007] Additionally, it is inconvenient to monitor a leak in the pipesor sprinkler head and to stop the leak in a conventional wet-pipesprinkler system. For instance, when the system operates due tomalfunction or breakage of the system, water pressurized in thesprinkler head or pipes floods neighboring areas. Damage may be enormouswhen such an accident occurs in a clean room where semiconductor devicesare manufactured, due to, for example, immersion of expensive tools formanufacturing semiconductor devices. In such a case, the water supplymust be blocked by shutting the main valve immediately and rapidlydraining water from a pipe to the location of the fire. However, in theconventional wet-pipe sprinkler system, valves are manually opened andclosed by a person, such as a system manager, and thus the process ofblocking water supply and draining water cannot be done immediately.Therefore, it is not possible to take quick measures when a pipe or asprinkler head is leaking, thereby resulting in water damage.

SUMMARY OF THE INVENTION

[0008] In an effort to solve the above problems, it is a feature of anembodiment of the present invention to provide a wet-pipe sprinklersystem capable of enacting rapid procedures when a pipe or a sprinklerhead is leaking.

[0009] It is another feature of an embodiment of the present inventionto provide a wet-pipe sprinkler system in which water hammering isminimized during the filling of a pipe with water.

[0010] It is still another feature of an embodiment of the presentinvention to provide a method of filling a wet-pipe sprinkler systemwith water while minimizing the occurrence of water hammering.

[0011] It is still another feature of an embodiment of the presentinvention to provide a method of minimizing damage due to the leakage ofa pipe or a sprinkler head of a wet-pipe sprinkler system.

[0012] To provide one feature of an embodiment of the present invention,there is provided a wet-pipe sprinkler system including a sprinklerhead; a plurality of interconnected pipes having two ends, the pluralityof interconnected pipes supplying water to the sprinkler head; at leastone water supply connected to one end of the plurality of interconnectedpipes; an electric main valve for controlling an inflow of water fromthe water supply to the plurality of interconnected pipes; an electricdrain valve connected to the other end of the plurality ofinterconnected pipes for draining the water from the plurality ofinterconnected pipes; and a first electrical control circuit installedin a central control studio for outputting a drain valve opening signalto the electric drain valve, which opens the electric drain valve, andfor outputting a first main valve closing signal to the electric mainvalve, which closes the main valve, in order to block water fromentering the plurality of interconnected pipes and to drain the watercontained in the plurality of interconnected pipes, if a leak occurs.

[0013] The plurality of interconnected pipes preferably include a mainpipe, having two ends, one end connected directly to the at least onewater supply, wherein the main pipe includes a water flow detector andan auxiliary valve; a water-filling pipe having two ends, both of whichare connected to the main pipe, wherein the water-filling pipe includesan inlet valve and an outlet valve; and an auxiliary pipe having twoends, one end connected to the other end of the main pipe away from theat least one water supply, wherein the auxiliary pipe includes thesprinkler head, wherein the electric main valve is connected to the mainpipe below the water flow detector, and the electric drain valve isconnected to the other end of the auxiliary pipe away from the mainpipe, and wherein one end of the water-filling pipe is connected belowthe main valve and the other end is connected above the auxiliary valve.

[0014] Preferably, the system further includes a pressure switch formeasuring a pressure in the auxiliary pipe and transmitting a signalindicating whether the pressure is at a normal level; and a controlpanel including a main valve control unit that outputs a second mainvalve closing signal to the electric main valve, which closes theelectric main valve when the pressure switch transmits a signalindicating that the pressure in the auxiliary pipe is not at the normallevel, so that the electric main valve is not able to be opened. Here,the main valve control unit may include a means for canceling the outputof the second main valve closing signal to the electric main valve.Preferably, the control panel further includes a state-indicative unitindicating the open or closed state of all valves installed in theplurality of interconnected pipes, and a signal that is generated by thepressure switch, indicating whether the pressure of the auxiliary pipeis at a normal level.

[0015] Preferably, the water-filling pipe further includes an electricintermediate valve between the inlet valve and the outlet valve, and thecontrol panel further includes a switch that is manipulated to transmita starting signal for opening the electric intermediate valve when thepipes or the sprinkler is supplied with water, and a timer that counts apredetermined time and transmits a time delay signal in response to thestarting signal. Preferably, the control panel further includes astate-indicative unit that indicates the open or closed state of allvalves installed in the plurality of interconnected pipes and a signalindicating whether the pressure in the auxiliary pipe is at a normallevel.

[0016] The sprinkler head may be installed in a clean room in whichsemiconductor devices are manufactured and may further include acontroller, which is placed in a passage of the clean room, to output adrain valve opening signal to the electric drain valve and a main valveclosing signal to the electric main valve.

[0017] In order to provide another feature of an embodiment of thepresent invention, a method of supplying water to the pipes in thewet-pipe sprinkler system according to an embodiment of the presentinvention includes verifying that the electric main valve and the inletvalve are closed, verifying that the auxiliary valve and the outletvalve are open, opening the inlet valve to supply water to the auxiliarypipe, checking the pressure in the auxiliary pipe, and opening theelectric main valve, if the pressure in the auxiliary pipe is at anormal level.

[0018] In order to provide another feature of an embodiment of thepresent invention, a method of supplying water to the pipes in thewet-pipe sprinkler system according to another embodiment of the presentinvention includes verifying that the electric main valve and theelectric intermediate valve are closed, verifying that the auxiliaryvalve, the inlet valve, and the outlet valve are open, manipulating theswitch to open the electric intermediate valve to supply water to theauxiliary pipe, receiving the time delay signal and checking thepressure in the auxiliary pipe, and opening the electric main valve, ifthe pressure in the auxiliary pipe is at a normal level.

[0019] Another feature of an embodiment of the present invention isprovided by a method of dealing with a leakage of the pipes or thesprinkler head in the wet-pipe sprinkler system according to anembodiment of the present invention including detecting a leakage,reporting the leakage to the central control studio when the leakage isdetected and outputting the drain valve opening signal to remotely openthe electric drain valve and the main valve closing signal to remotelyclose the electric main valve via the first electrical control circuitin the central control studio.

[0020] Another feature of an embodiment of the present invention isprovided by a method of dealing with a leakage of the pipes or thesprinkler head in the wet-pipe sprinkler system according to anotherembodiment of the present invention including manipulating thecontroller to output the drain valve opening signal and the first mainvalve closing signal when the leakage is discovered, so that theelectric drain valve and the electric main valve are controlled to beopened and closed, respectively.

[0021] According to the present invention, it is possible to take rapidactions when a pipe or a sprinkler head is leaking, thus minimizingdamage due to water leakage. Further, it is possible to fill the pipeswith water such that the occurrence of water hammering is minimized.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other features and advantages of the presentinvention will become more apparent upon review of a detaileddescription of preferred embodiments thereof with reference to theattached drawings in which:

[0023]FIG. 1 illustrates a view of a wet-pipe sprinkler system accordingto a first embodiment of the present invention;

[0024]FIG. 2 illustrates a view of a wet-pipe sprinkler system accordingto a second embodiment of the present invention;

[0025]FIG. 3 is a flow chart of a method of filling the wet-pipesprinkler system shown in FIG. 2 with water;

[0026]FIG. 4 illustrates a view of a wet-pipe sprinkler system accordingto a third embodiment of the present invention;

[0027]FIG. 5 is a flow chart of a method of supplying water to thewet-pipe sprinkler system of FIG. 4;

[0028]FIG. 6 is a flow chart of a method of dealing with leakage in awet-pipe sprinkler system according to the various embodiments of thepresent invention;

[0029]FIG. 7 illustrates a diagram of a modified wet-pipe sprinklersystem according to the first embodiment; and

[0030]FIG. 8 is a flowchart illustrating a method of dealing withleakage of the wet-pipe sprinkler system shown in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

[0031] Korean Patent Application No. 2001-62153, entitled “Wet-PipeSprinkler System, Method of Supplying Water and Dealing With Water Leakin the Sprinkler System,” filed on Oct. 9, 2001, is incorporated byreference herein in its entirety.

[0032] The present invention will now be described more fully withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as being limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the concept of the invention to those skilled in the art. In thedrawings, the shapes of constitutional elements are exaggerated forclarity. Like reference numerals in different drawings represent thelike elements and thus their description will be omitted.

[0033] First Embodiment

[0034]FIG. 1 illustrates a view of a wet-pipe sprinkler system 100(hereinafter, ‘system 100’) according to a first embodiment of thepresent invention. Referring to FIG. 1, the system 100 includes asprinkler head 180, interconnected pipes P₁, P₂, P₃ that supply water tothe sprinkler head 180, and a water supply 102 connected to one end ofthe pipe P₁.

[0035] The structure of the water supply of a wet-pipe sprinkler systemmay vary according to the shape of a housing or structure, in which thesystem is provided. The system 100, however, adopts as an exemplarywater supply 102 a water tank that is supplied with water by a fire pumpand that delivers the water supplied to the other components. Further,an auxiliary tank such as an elevated tank may be further included as asupplementary water source. The fire pump may be used with a pump havinga discharge capacity such that water is simultaneously discharged fromeight to forty sprinkler heads at 80 liters/minute.

[0036] Water contained in the water supply 102 is supplied to a mainpipe P₁ or a water-filling pipe P₂ The water-filling pipe P₂ has twoends, both of which are connected to the main pipe P₁. In addition, anauxiliary pipe P₃ including the sprinkler head 180 is connected to themain pipe P₁. A pipe having a large diameter is chosen as the main pipeP₁ according to the discharge rate of a fire pump. For example, a 60-250mm-wide pipe may be used. The diameter of the water-filling pipe P₂ mustbe smaller than that of the main pipe P₁, e.g., a 40 mm-wide pipe, sothat the flow of water into the auxiliary pipe P₃ occurs slowly enoughto minimize water hammering. If the water flows into the auxiliary pipeP₃ too rapidly, water hammering will occur.

[0037] The main pipe P₁ is a riser pipe that is installed perpendicularto the ground. An electric main valve 110, a water flow detector 115,and an auxiliary valve 120 are installed on the main pipe P₁. Theelectric main valve 110 controls the overall inflow of water into thepipes P₁, P₂, P₃ from the water supply 102. Unlike in conventionalwet-pipe sprinkler systems, in the first embodiment of the presentinvention, the main valve 110 is an electric valve. A valve, which isusually called an ‘alarm check valve,’ is selected as the water flowdetector 115 as in conventional wet-pipe sprinkler systems, and detectsif the sprinkler head 180 is open. In other words, when the sprinklerhead 180 is open and water contained therein is sprayed at a fire, waterin the auxiliary pipe P₃ flows to the sprinkler head 180, and water inthe main pipe P₁ also flows to the sprinkler head 180. As a result, thewater flow detector 115 operates. When the pressure in the auxiliarypipe P₃ decreases, a clapper in the water flow detector 115 is openeddue to the water pressure in the main pipe P₁, thus allowing water toflow into the auxiliary pipe P₃. The water flow detector 115 may furtherinclude a pressure switch (not shown) that detects the pressure in themain pipe P₁ and also a test connection pipe 117 including a manualvalve used to check periodically if the water flow detector 115 operatesnormally. The auxiliary valve 120, which is opened and closed bymanipulating a handle thereof, is normally open.

[0038] The water-filling pipe P₂ is a pipe used for supplying water tothe auxiliary pipe P₃ and has two ends that are connected to the mainpipe P₁ below the electric main valve 110 and above the auxiliary valve120. Also, an inlet valve 130 and an outlet valve 135, which are manualvalves, are installed on the water-filling pipe P₂. A check valve 142may be further installed between the inlet valve 130 and the outletvalve 135. The check valve 142 is a valve that enables water to flow inone direction, thereby preventing back flow, and may be a lift checkvalve or a swing check valve.

[0039] In the first embodiment of the present invention, the auxiliarypipe P₃ includes: a lateral pipe 162, which is connected perpendicularlyto the main pipe P₁; a first branch pipe 164 branching away from thelateral pipe 162; and a second branch pipe 166 which branches outupwardly and away from the first branch pipe 164 and a portion of whichis bent downward. Here, the number of the first and second branch pipes164 and 166 may be increased to a desired number. The sprinkler head 180is installed at one end of the second branch pipe 166. Unlike a lowerpipe adopted in a sprinkler system, the second branch pipe 166 isinstalled to diverge upwardly with a portion bent downward to preventsediment from accumulating in the sprinkler head 180. Although FIG. 1shows that the second branch pipe 166 branches out from the first branchpipe 164, which branches from the lateral pipe 162, pipes may be set tobranch out directly from the main pipe P₁ or the first branch pipe 164by a predetermined number, as it demands, in the respective sprinklersystem. Diameters of the lateral pipe 162, the first branch pipe 164 andthe second branch pipe 166, which constitute the auxiliary pipe P₃, arenot always required to be larger than the diameter of the main pipe P₁,but the diameter, material and thickness of a pipe must be considered sothat a pipe can operate for a sufficient period of time under highpressure. For example, it is possible to select a 150 mm-wide pipe, a 65mm-wide pipe, and a 25 mm-wide pipe as the lateral pipe 162, the firstbranch pipe 164, and the second branch pipe 166, respectively.

[0040] An air vent 175 may be included in the auxiliary pipe P₃ toalleviate any impact of water pressure applied to the auxiliary pipe P₃when a pipe is supplied with water. Further, a manual valve 178, whichis normally open, may be installed at the bottom of the air vent 175.Referring to FIG. 1, an air vent 175 and one manual valve 178 areinstalled on the auxiliary pipe P₃ as a pair, but the numbers thereofmay be increased or decreased as necessary.

[0041] A test box 185 including a manual valve may be further installedat one end of the auxiliary pipe P₃. During normal conditions, themanual valve in the test box 185 is closed. The test box 185 is used todrain stagnant water from the auxiliary pipe P₃ during periodicalchecking of the system 100. Opening the manual valve of the test box 185results in draining water, thereby removing any sediment present. Also,an electric drain valve 190 that drains water contained in the pipes P₁,P₂, P₃ is further installed at an end of the auxiliary pipe P₃.

[0042] Additionally, in the system 100, a first electrical controlcircuit 310 is included to allow a central control studio 300 to outputa drain valve opening signal to the electric drain valve 190, whichopens the electric drain valve 190, and a main valve closing signal tothe electric main valve 110, which closes the electric main valve 110.In the event that the pipes P₁, P₂, P₃ or the sprinkler head 180 isleaking, the electric main valve 110 is remotely controlled to be closedvia the first electrical control circuit 310, so that water canimmediately be prevented from entering the pipes P₁, P₂, P₃. Further,water contained in the pipes P₁, P₂, P₃ may be rapidly released byopening the electric drain valve 190.

[0043] A conventional wet-pipe sprinkler system includes a main manualvalve but does not include the electric drain valve 190 according to thepresent invention. Accordingly, when a leak occurs in a conventionalsystem, in order to block the supply of water to the pipes, the mainmanual valve must be manipulated, and in order to release water from thepipes, the manual valve of the test box 185 must be manipulated. Inother words, all valves of the system are manually manipulated by asystem manager and thus, it is virtually impossible to deal with theleak rapidly.

[0044] In contrast, according to the first embodiment of the presentinvention, it is possible to deal with any leakage of the pipes P₁, P₂,P₃ or the sprinkler head 180 quickly, thereby minimizing damage due tothe submergence or wetting of surroundings.

[0045] A method of dealing with a leakage of the system 100 will now bedescribed with reference to FIGS. 1 and 6.

[0046] When a system manager or the like becomes aware of a leakage inthe pipes P₁, P₂, P₃, or the sprinkler head 180 (step m1), he or shereports this fact to a central control studio 300, which may located ata remote location (step m2). When the central control studio 300receives the report, it transmits a drain valve opening signal to theelectric drain valve 190, which opens the electric drain valve 190, anda main valve closing signal to the electric main valve 110, which closesthe electric main valve 110. Thus, the central control studio 300remotely controls the opening of the electric drain valve 190 and theclosing of the electric main valve 110 (step m3).

[0047] According to the first embodiment of the present invention, it ispossible to immediately open the electric drain valve 190 remotely toallow immediate drainage of the water from the pipes P₁, P₂, P₃ even ifthe pipes P₁, P₂, P₃ or the sprinkler head 180 is leaking. Further, itis possible to immediately block any additional supply of water fromentering the pipes P₁, P₂, P₃ by rapidly closing the electric main valve110 remotely, thereby minimizing an amount of water leaked from thepipes P₁, P₂, P₃ or the sprinkler head 180.

[0048] Meanwhile, FIG. 7 shows a modified example of the wet-pipesprinkler system 100 according to the first embodiment of the presentinvention that may be installed in a clean room 320 where semiconductordevices are manufactured.

[0049] Referring to FIG. 7, a controller 340 is further installed at apassage of the clean room 320 so that the drain valve opening signal andthe main valve closing signal may be output to the electric drain valve190 and the electric main valve 110, respectively, via a secondelectrical control circuit 330. Therefore, when a system manager detectsa leakage in the pipes P₁, P₂, P₃ or the sprinkler head 180 to beleaking, he or she can deal with the leakage as described with referenceto FIG. 6 or as later explained with reference to FIG. 8.

[0050] Referring to FIG. 8, if a system manager detects a leakage of thepipes P₁, P₂, P₃ or the sprinkler head 180 (step p1), he or she movesfrom a point of the leak to a passage of the clean room 320. Then, he orshe manipulates a switch of the controller 340 to transmit a drain valveopening signal to the electric drain valve 190, which opens the electricdrain valve 190, and a main valve closing signal to the electric mainvalve 110, which closes the electric main valve 110. As a result, theelectric drain valve 190 and the electric main valve 110 may be openedand closed, respectively, remotely (step p2).

[0051] In conclusion, a system manager is able to deal with the leakageof the pipes P₁, P₂, P₃ or the sprinkler head 180 by manipulating thecontroller 340 to open the electric drain valve 190 and close theelectric main valve 110. Alternatively, the system manager may reportthe leak to the central control studio 300, which may be at a remotelocation, so that the central control studio 300 may remotely controlthe electric drain valve 190 to be opened and the electric main valve110 to be closed.

[0052] Second Embodiment

[0053]FIG. 2 illustrates a view of a wet-pipe sprinkler system 200according to a second embodiment of the present invention. In FIG. 2,the same elements as those shown in the wet-pipe sprinkler system 100 ofFIG. 1 are illustrated with the same reference numerals. Thus,descriptions thereof will be omitted here.

[0054] Referring to FIG. 2, in comparison with FIG. 1, an auxiliary pipeP₃ further includes a pressure switch 170 that measures the pressure inthe auxiliary pipe P₃ and transmits a signal indicating whether thepressure is at a normal level. Thus, in the wet-pipe sprinkler system200 (hereinafter, ‘system’), pressure in the auxiliary pipe P₃ may betwice monitored by using the pressure switch 170 and by using a pressureswitch included in the test connection pipe 117.

[0055] The system 200 further includes a control panel 145 having a mainvalve control unit 157. The main valve control unit 157 receives asignal indicating abnormal pressure in the auxiliary pipe P₃ from thepressure switch 170 and outputs a main valve closing signal to theelectric main valve 110 to close the electric main valve 110, so thatthe electric main valve 110 cannot be manually opened. The main valvecontrol unit 157 may further include means for canceling output of themain valve closing signal to the electric main valve 110 in case of anemergency. The control panel 145 further includes a state-indicativeunit 159 that indicates the opening or closing of all valves installedin pipes P₁, P₂, P₃ and indicates a normal/abnormal pressure signalgenerated by the pressure switch 170. For instance, the state-indicativeunit 159 may have a green light lit when these valves are in a normalstate and the pressure in the auxiliary pipe P₃ is at a normal level,and may have a red light lit otherwise.

[0056] A method of supplying water to the system 200 of FIG. 2 will nowbe explained with reference to FIGS. 2 and 3.

[0057] First, a system manager or the like checks the system 200 toverify that the electric main valve 110 and inlet valve 130 are closed(step f1). Next, he or she verifies that the auxiliary valve 120 and theoutlet valve 135 are open (step f2). Then, the open or closed state ofthe valves in the system 200 are checked using the state-indicative unit159 included in the control panel 145.

[0058] Once the electric main valve 110 and inlet valve 130 areconfirmed closed, and the auxiliary valve 120 and outlet valve 135 areconfirmed open, the inlet valve 130 is opened to supply water to thesystem 200 (step f3). Then, the pressure in the auxiliary pipe P₃ ischecked to see if it is at a normal level using the state-indicativeunit 159 (step f4). In the event that the pressure in the auxiliary pipeP₃ is not at a normal level, the pipes P₁, P₂, P₃ are checked for leaks,a manual valve attached to the test box 185 is checked to see if it isopen, and the electric drain valve 190 is checked to see if it is open.If the pressure switch 170 transmits a signal indicating that thepressure in the auxiliary pipe P₃ is at a normal level, the auxiliarypipe P₃ is completely filled with water, and thus the electric mainvalve 110 is opened (step f5). The electric main valve 110 may be openedmanually.

[0059] The main valve control unit 157 in the control panel 145 outputsa main valve closing signal to the electric main valve 110, which closesthe electric main valve 110, so that the electric main valve 110 cannotbe manually opened when the pressure switch 170 transmits a signalindicating abnormal pressure in the auxiliary pipe P₃. Thus, in theevent that a system manager mistakenly tries to manually open theelectric main valve 110 prior to the complete supply of water to theauxiliary pipe P₃, the system manager will not be able to, because theelectric main valve 110 is not able to be opened. This safeguard ofensuring that the electric main valve 110 remains closed when thepressure in the auxiliary pipe P₃ is abnormal helps minimize anoccurrence of water hammering. However, the main valve control unit 157includes means for canceling the output of the main valve closing signalto the electric main valve 110 in case of an emergency. Therefore, it ispossible to manually open the electric main valve 110 even though thepressure in the auxiliary pipe P₃ is not at a normal level.

[0060] Meanwhile, the method of dealing with the leakage of thesprinkler head 180 or the pipes P₁, P₂, P₃ explained with reference toFIG. 3 may be applied to the system 100. Further, the method of dealingwith the leakage explained with reference to FIG. 8 may also be appliedto the system 200 if the controller 340 is included in the system 200 asin the modified example of the first embodiment.

[0061] In a wet-pipe sprinkler system according to embodiments of thepresent invention, leakage of pipes or a sprinkler head may be stoppedimmediately, thereby minimizing damage due to the submergence or wettingof surroundings from water leaked from the pipes or sprinkler head,unlike in a conventional wet-pipe sprinkler system in which all valvesare manipulated by a system manager. Also, it is possible to supplywater to pipes or a sprinkler head, suppressing the occurrence of waterhammering. In addition, the pressure in an auxiliary pipe may be twicemonitored.

[0062] Third Embodiment

[0063]FIG. 4 illustrates a view of a wet-pipe sprinkler system 400according to a third embodiment of the present invention. In FIG. 4, thesame components as those shown in the wet-pipe sprinkler systems 100 and200 according to the first and second embodiments of the presentinvention, respectively, are illustrated with like reference numerals.As may be seen in FIG. 4, the wet-pipe sprinkler system 400(hereinafter, ‘system’) has almost the same structure as the wet-pipesprinkler system 200. Thus, descriptions of like components will beomitted here.

[0064] Referring to FIG. 4, a water-filling pipe P₂ further includes anelectric intermediate valve 140 between an inlet valve 130 and outletvalve 135. The electric intermediate valve 140 is a valve that is turnedon and off to control the rate at which water flows.

[0065] As in the control panel 145 shown in FIG. 2, a control panel 145′includes a main valve control unit 157 that outputs a main valve closingsignal to the electric main valve 110, which closes the electric mainvalve 110, when a pressure switch 170 receives a signal indicating anabnormal pressure in an auxiliary pipe P₃. Here, the main valve controlunit 157 may include means for canceling the output of the main valveclosing signal to the electric main valve 110 in case of an emergency.In a state-indicative unit 159′ included in the control panel 145′, itis possible to check whether all valves installed in pipes P₁, P₂, P₃are open or closed and if a signal output from the pressure switch 170indicates whether the pressure in the auxiliary pipe P₃ is at the normallevel. For instance, as the state-indicative unit 159 shown in FIG. 2,the state-indicative unit 159′ may have a green light lit when valvesare in normal states and the auxiliary pipe P₃ is at a normal pressurelevel, and may have a red light lit otherwise.

[0066] The control panel 145′ further includes a switch 150 that ismanipulated to send a starting signal which opens the electricintermediate valve 140 when the pipes P₁, P₂, P₃and a sprinkler head 180are supplied with water; and a timer 155 that counts a predeterminedtime and sends a time delay signal in response to the starting signal.The predetermined time is a time needed for supplying water to theauxiliary pipe P₃ and can be easily measured considering the volume ofthe water to be supplied to the auxiliary pipe P₃ in respect to thespeed of the sampling water by a fire pump and the width and length ofpipes. The time required for the supply of water is input to the timer155 in advance. When the supply of water and counting of the input timeare complete, the timer 155 generates a sound signal or generates a redflashing light in the state-indicative unit 159′, so that a time delaysignal is sent to a system manager when the time input is counted withthe supply of water. The supply of water begins together withmanipulation of the switch 150, and ends after a system manager receivesthe time delay signal, checks the pressure of the auxiliary pipe P₃ fromthe pressure switch 170, and opens the electric main valve 110 afterreceiving the time delay signal.

[0067] Hereinafter, a method of supplying water to the system 400 willbe explained with reference to FIGS. 4 and 5.

[0068] First, a system manager verifies that the electric main valve 110and the electric intermediate valve 140 in the system 400 are closed(step h1). Then, the system manager verifies that the auxiliary valve120, the inlet valve 130, and the outlet valve 135 are open (step h2).The open or closed state of all valves may be checked using thestate-indicative unit 159′ included in the control panel 145′.

[0069] After confirming that the electric main valve 110 and theelectric intermediate valve 140 are closed and that the auxiliary valve120, inlet valve 130 and outlet valve 135 are open, the switch 150 ismanipulated to open the electric intermediate valve 140, so that wateris supplied to the sprinkler head 180 or the pipes P₁, P₂, P₃ (step h3).When a starting signal for opening the electric intermediate valve 140is generated from the switch 150, the timer 155 receives the startingsignal and transmits a time delay signal when the time input lapses. Thetime delay signal is transmitted as a sound or red flashing light to asystem manager. The system manager, after having received the time delaysignal, checks if the pressure of the auxiliary pipe P₃ is at a normallevel by looking at the state-indicative unit 159′ (step h4). If thepressure is not at a normal level, pipes P₁, P₂, P₃ are checked forleakage, and a manual valve in the test box 185 or the electric drainvalve 190 are checked for being open, and necessary measures are taken.Alternatively, if the pressure of the auxiliary pipe P₃ is at a normallevel, the auxiliary pipe P₃ has been completely supplied with water andtherefore, the electric main valve 110 is opened (step h5). The electricmain valve 110 may be opened manually.

[0070] The main valve control unit 157 installed in the control panel145′ outputs a main valve closing signal to the electric main valve 110when a signal indicating that the pressure of the auxiliary pipe P₃ isnot at a normal level, so that the electric main valve 110 is not ableto be opened. Therefore, it is possible to prevent the electric mainvalve 110 from being mistakenly opened until the auxiliary pipe P₃ iscompletely supplied with water, thus minimizing the occurrence of waterhammering. However, the main valve control unit 157 also includes meansfor canceling the output of the main valve closing signal to theelectric main valve 110 in case of an emergency. Thus, it is possible toopen the electric main valve 110 even though the pressure in theauxiliary pipe P₃ is not at a normal level.

[0071] The method of dealing with the leakage of a wet-pipe sprinklersystem explained with reference to FIG. 6 may be used in the system 400according to the third embodiment of the present invention. Also, if thecontroller 340 shown in the modified example of the first embodiment isincluded in the system 400, the method of dealing with the leakage of awet-pipe sprinkler system explained with reference to FIG. 8 may also beused in the system 400.

[0072] It is possible, according to the embodiments of the presentinvention described above, to deal with leakage in the pipes or asprinkler head of a sprinkler system rapidly, unlike in a conventionalwater-pipe sprinkler system in which all valves must be manipulated by asystem manager. As a result of being able to rapidly and effectivelycontrol a leak, damage caused by submergence or wetting from the leakmay be minimized.

[0073] Also, according to the present invention, it is possible topromptly deal with the leakage of pipes or a sprinkler head in a remotecentral control studio located at a predetermined spot, thus minimizingdamage caused by submergence or wetting from the leak.

[0074] Further, a pressure switch and a control panel including a mainvalve control unit may be installed in a wet-pipe sprinkler systemaccording to an embodiment of the present invention. Thus, it ispossible to prevent a main valve from being mistakenly opened by asystem manager when the pressure in an auxiliary pipe is not at a normallevel due to an incomplete supply of water. Accordingly, a sprinklersystem or pipes may be supplied with water, minimizing the occurrence ofwater hammering. Also, the pressure in the pipes, particularly anauxiliary pipe, may be twice monitored.

[0075] Including a switch and timer in the control panel enables asprinkler system or pipes to be conveniently and efficiently suppliedwith water, thereby enhancing the work efficiency of equipment, and fora system manager.

[0076] With a sprinkler system, it is possible to save lives andproperty by extinguishing a fire at a beginning stage. For instance,damage may be dramatically reduced when a wet-pipe sprinkler systemaccording to the present invention is installed in a clean room wheresemiconductor devices are manufactured. Also, should a sprinkler head orpipes leak in a wet-pipe sprinkler system according to the presentinvention, the leakage may be promptly dealt with, thereby preventingdamage due to the submergence or wetting of expensive tools formanufacturing semiconductor devices.

[0077] Preferred embodiments of the present invention have beendisclosed herein and, although specific terms are employed, they areused and are to be interpreted in a generic and descriptive sense onlyand not for purpose of limitation. Accordingly, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made without departing from the spirit and scope of thepresent invention as set forth in the following claims.

What is claimed is:
 1. A wet-pipe sprinkler system comprising: asprinkler head; a plurality of interconnected pipes having two ends, theplurality of interconnected pipes supplying water to the sprinkler head;at least one water supply connected to one end of the plurality ofinterconnected pipes; an electric main valve for controlling an inflowof water from the water supply to the plurality of interconnected pipes;an electric drain valve connected to the other end of the plurality ofinterconnected pipes for draining the water from the plurality ofinterconnected pipes; and a first electrical control circuit, in acentral control studio, installed for outputting a drain valve openingsignal to the electric drain valve, which opens the electric drainvalve, and for outputting a first main valve closing signal to theelectric main valve, which closes the electric main valve, in order toblock water from entering the plurality of interconnected pipes and todrain the water contained in the plurality of interconnected pipes, if aleak occurs.
 2. The system as claimed in claim 1, wherein the pluralityof interconnected pipes comprise: a main pipe having two ends, one endconnected directly to the at least one water supply, wherein the mainpipe includes a water flow detector and an auxiliary valve; awater-filling pipe having two ends, both of which are connected to themain pipe, wherein the water-filling pipe includes an inlet valve and anoutlet valve; and an auxiliary pipe having two ends, one end connectedto the other end of the main pipe away from the at least one watersupply, wherein the auxiliary pipe includes the sprinkler head, whereinthe electric main valve is connected to the main pipe below the waterflow detector, and the electric drain valve is connected to the otherend of the auxiliary pipe away from the main pipe, and one end of thewater-filling pipe is connected below the main valve and the other endis connected above the auxiliary valve.
 3. The system as claimed inclaim 2 further comprising: a pressure switch for measuring a pressurein the auxiliary pipe and transmitting a signal indicating whether thepressure is at a normal level; and a control panel including a mainvalve control unit that outputs a second main valve closing signal tothe electric main valve, which closes the electric main valve when thepressure switch transmits a signal indicating that the pressure in theauxiliary pipe is not at a normal level, so that the electric main valveis not able to be opened.
 4. The system as claimed in claim 3, whereinthe main valve control unit comprises a means for canceling the outputof the second main valve closing signal to the electric main valve. 5.The system as claimed in claim 4, wherein the control panel furthercomprises a state-indicative unit indicating the open or closed state ofall valves installed in the plurality of interconnected pipes, and asignal that is generated by the pressure switch, indicating whether thepressure of the auxiliary pipe is at a normal level.
 6. The system asclaimed in claim 4, wherein the water-filling pipe further comprises anelectric intermediate valve between the inlet valve and the outletvalve, and the control panel further includes a switch that ismanipulated to transmit a starting signal for opening the electricintermediate valve when the pipes or the sprinkler is supplied withwater, and a timer that counts a predetermined time and transmits a timedelay signal in response to the starting signal.
 7. The system asclaimed in claim 6, wherein the control panel further comprises astate-indicative unit that indicates the open or closed state of allvalves installed in the plurality of interconnected pipes and a signalindicating whether the pressure in the auxiliary pipe is at a normallevel.
 8. The system as claimed in claim 1, wherein the sprinkler headis installed in a clean room in which semiconductor devices aremanufactured and further comprising a controller, which is placed in apassage of the clean room, to output the drain valve opening signal tothe electric drain valve and the first main valve closing signal to theelectric main valve.
 9. A method of supplying water to the pipes in thewet-pipe sprinkler system of claim 5, the method comprising: verifyingthat the electric main valve and inlet valve are closed; verifying thatthe auxiliary valve and outlet valve are open; opening the inlet valveto supply water to the auxiliary pipe; checking the pressure in theauxiliary pipe; and opening the main valve, if the pressure in theauxiliary pipe is at a normal level.
 10. A method of supplying water tothe plurality of interconnected pipes in the wet-pipe sprinkler systemas claimed in claim 7, the method comprising: verifying that theelectric main valve and the electric intermediate valve are closed;verifying that the auxiliary valve, the inlet valve, and the outletvalve are closed; manipulating the switch to open the electricintermediate valve to supply water to the auxiliary pipe; receiving thetime delay signal and checking the pressure in the auxiliary pipe; andopening the main valve, if the pressure in the auxiliary pipe is at anormal level.
 11. A method of dealing with a leakage of the pipes or thesprinkler head in the wet-pipe sprinkler system as claimed in claim 1,the method comprising: detecting a leakage; reporting the leakage to thecentral control studio when the leakage is detected; and outputting thedrain valve opening signal to remotely open the electric drain valve andthe first main valve closing signal to remotely close the electric mainvalve via the first electrical control circuit in the central controlstudio.
 12. A method of dealing with a leakage of the plurality ofinterconnected pipes or the sprinkler head in the wet-pipe sprinklersystem as claimed in claim 8, the method comprising manipulating thecontroller to output the drain valve opening signal and the first mainvalve closing signal when the leakage is discovered, so that theelectric drain valve is opened and the electric main valve is closed.